1. Technical Field
This disclosure relates to a process for separating components from a feed solution of glucose and fructose mixture into liquid glucose and liquid fructose for producing high fructose corn syrup (HFCS), wherein the feed solution is obtained from preceding operation. It employs a new mass transfer method, a method that is different from traditional packed bed process, to eliminate displacement zone and fully utilize void volume in batch chromatography to retrieve glucose and fructose solution and meanwhile to elevate the concentration level of retrieved solutions.
2. The Description of Prior Art
It is known that the batch process been commonly used for separation between glucose and fructose contained in a feed solution is by inputting such feed solution through a fixed bed of cation exchange column, then, following by a de-ionized water to attain such purpose. As taught by U.S. Pat. No. 3,044,904, U.S. Pat. No. 4,472,203, U.S. Pat. No. 4,395,292, Japanese Pat. No. 24,807 of 1970 and many other unlisted disclosures, without exceptions, the separation is carried out through so-called chromatography, which is a long column packed with a stationary resin. The separation is achieved through resembling mass transfer phenomenon or mechanism that the eluent water is flowing through a part of the stationary resin together with the feed solution, in a zone so-called mass transfer zone. As such mass transfer zone being transported by continuous pushing the eluent water behind the feed solution, the fructose contained in the feed solution is been retained by the resin to a greater degree than glucose. At any instance of chromatographic operation, the part of resin contributed for such separation is only when the zone passed by, while the remaining of resin is idling. By pushing such eluent water behind the feed solution, the so-called displacement zone, which contributes nothing for separation, is emerged first as the eluent water pushes off previously introduced feed solution through resin bed in order to proceed separation within said mass transfer zone. Given that various methods and processes were developed through said mechanism, the chromatography has been broadly recognized and implemented as the standard separation method that has unavoidably inherited with aforementioned shortcomings for not being efficiently utilizing the resin. Mainly because such fundamental mechanism has not been further improved, therefore, the chromatography could consume resin and eluent more efficiently and yet could gain better separation. In fact, several factors briefly illustrated afterward are multifaceted coexisted affecting one another and are responsible for those imperfections experienced in traditional chromatographic operation.
Inefficient usage of resin as previous illustration, the mass transfer proceeds only at the very front end of mass transfer zone, thus the remaining resin prior to and after such zone are idle; PA0 Due to the existence of displacement zone to create excess dilution and to increase cycle time, and thus, even further enhances inefficient usage of resin; PA0 Native engineering drawbacks of column process are listed as following; PA0 Requires longer cycle time to further weaken effective consumption of resin and eluent, to further intensify said engineering drawbacks; and PA0 Exhibits high-pressure drop and difficulty in maintenance, as huge throughput demand requires relative increment of resin inventory.
1. Flow dynamics: axial dispersion, diffusion effects and back mixing of column end effects are primary factors in deteriorating the separation quality. PA1 2. Column geometry: in and out column end-effects plus dead volume in fluid delivery further enhance the effects of flow dynamics. PA1 3. Loading limitation: due aforementioned flow dynamics, loading limitation is unavoidably imposed to avoid peak broadening, overlapping, and tailing to compromise with separation quality. PA1 1. Retain solid phase material in a cell having an inlet on top side and an outlet on bottom side with meshed filter to retain said material from being drained. PA1 2. Intermittently deliver an amount of liquid phase material to wet a part of solid phase material during a first time period. PA1 3. Intermittently supply pressurized gas to the cell on the inlet side following each delivery of a liquid material during a second time period to increase the flow rate of delivered liquid through said material to complete expected mass transfer to promote absorption of dissolved components in liquid phase material onto said solid phase material and/or elution of absorbed components from said solid phase material. PA1 4. Maintain a vacuum on the outlet side of solid phase material to maintain said material in a semi-dry status or partial dry status, wherein partial dry status is defined as majority of the delivered liquid material having been drained off in parts by the vacuum and pressurized gas during the second time period. PA1 5. Intermittently collecting most of treated solution from the outlet of cell during a third time period. PA1 6. Total time spent from steps 2 to 5 is defined as minimal time interval.
An improved simulated moving bed process, abbreviated as SMB, is taught in both Japanese Provisional Patent Publication No. 26336 of 1978 in which zeolite is used as resin and Japanese Provisional Patent Publication No. 88355 of 1978 in which a cation exchange resin is used. The process compromises multiple columns connected in series, each column has its distributors to allow fluid to flow into and out of such column. Actually, each column in such series connection represents a particular mass-transfer task compared to a long column to carry out all tasks in sequence. At a setting time interval, all points of feed loading, eluent introducing, product and by-product withdrawals are shifted simultaneously purposely for cutting down resin and eluent consumption. Unlike rapid virtue of high ion mobility and electrical actions in water ion exchange reactions, the glucose and fructose separations are very slow. These sugars are non-electrolytes and the separation is governed by a very narrow difference interaction between resin and the dissolved sugar components in feed solution. An additional factor in affecting such interaction difference is water content within the mobile phase. It undermines such interaction to minimal when too much water exists due sugars are very soluble in water. Despite various difficult natures, the general practice of SMB operates at a flow rate of 0.8 to 1.0 bed-volume per hour, so that, the separation can be attained based on small interaction difference between sugar components and resin. In the other words, the process takes 1 to 1.25 hours to complete a separation cycle. Nevertheless, the loading limitation is set between a ratio of 0.05 and 0.1 feed-rate to resin bed volume as the operation guideline for obtaining acceptable separation quality versus operation efficiency. For example, a feed input rate of 200 gallons per minute will consume 2000 gallons of resin per minute based on a ratio of 0.1 feed-rate to resin bed volume. For a 1 to 1.25 hours cycle time, it will consume between 120,000 and 150,000 gallons of resin. In viewpoints of excess resin being used in chromatographic process, excess eluent has to be coped in order to push off the separated fractions. It surprisingly consumes about two times of eluent water as feed input rate. Overall speaking, the SMB process is far superior to a single fixed bed process in aspects of resin consumption and operation efficiency between product yield and separation quality. Therefore, it has been overwhelmingly adopted as the standard industrial process ever since was first introduced. However, this process is still limited by using general mechanism in chromatography with attempting in manipulating the column configuration and optimization in fluid distribution, in which the process still inherits the aforementioned native engineering drawbacks. Process disclosed herein proceeds like SMB, and yet, in a single bed or multiple beds in a bundle, through which conducts as a batch operation mode. Furthermore, when this disclosure compares with SMB, it aims to consume much less resin and eluent to gain the separated glucose and fructose in a much higher concentration with ultimate purity and yield, but in a much lower production cost.